In cone beam computed tomography (cone beam CT; CBCT), an imager in which an X-ray source and a two-dimensional detector form a pair captures a two-dimensional radiographic image by emitting cone-shaped X-rays from the X-ray source to the two-dimensional detector while rotating around an imaging target to change the irradiation angle. By using the cone-shaped X-rays, in the cone beam CT, it is possible to generate (reconstruct) a CT image (tomographic image) by capturing a two-dimensional radiographic image without the need to rotate the imaging target during imaging and without the need for multiple rotations.
Here, when performing a CT scan for the human body as a target, if subject blur due to the breathing of the imaging target occurs, this becomes a factor lowering the accuracy of the CT image. In order to prevent such a subject blur, a method is used in which an imaging target holds their breath during imaging. However, an increase in the breath-holding time becomes a burden for the imaging target. Therefore, in order to acquire a high-accuracy image while reducing the burden on the imaging target, it is preferable that the imaging time be short.
As an apparatus capable of reducing the imaging time, there is a CBCT for keeping the relatively small rotation angle of each imager by using a plurality of imagers, such as a dual-source CBCT using two pairs of imagers (for example, PTL 1).